Hospital Ship 4-2 was a Dinaali hospital ship. The ship was commanded by Chellick, and controlled by an artificial intelligence program called "the allocator", which served to distribute available resources most efficiently. It was also equipped with an unknown type of device that allowed it to levitate above the surface of a planet in need of its services.

The ship was divided into several levels designated by colors:

Level Blue was where patients with a high treatment coefficient (T.C.) were treated. This level had the best conditions and treatments, because patients there were deemed to be the most valuable to society, such as a chief engineer.

Level Red was where patients with a lower T.C. were treated. Such patients were deemed to be less valuable to society, and thus fewer resources were given to this level. Due to more people being on this level, there were often long waits for what few resources were available. Proton imaging was one such example.

Level Yellow was where some patients from Level Red were sent after they were stabilized enough to be moved.

Level Green was for patients with an even lower T.C. This level had even less medical equipment than Level Red.